The MHC-haplotype influences primary, but not memory, immune responses to an immunodominant peptide containing T- and B-cell epitopes of the caprine arthritis encephalitis virus Gag protein

Vaccine ◽  
2006 ◽  
Vol 24 (5) ◽  
pp. 597-606 ◽  
Author(s):  
Alexandra Fluri ◽  
Chiara Nenci ◽  
Marie-Luise Zahno ◽  
Hans-Rudolf Vogt ◽  
Shiv Charan ◽  
...  
2012 ◽  
Vol 93 (1) ◽  
pp. 50-60 ◽  
Author(s):  
En-Cheng Sun ◽  
Jing Zhao ◽  
Ni-Hong Liu ◽  
Tao Yang ◽  
Jian-Nan Ma ◽  
...  

West Nile virus (WNV) non-structural protein 1 (NS1) elicits protective immune responses during infection of animals. WNV NS1-specific antibody responses can provide the basis for serological diagnostic reagents, so the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the conservation of these sites among the Japanese encephalitis virus (JEV) serocomplex members also needs to be defined. The present study describes the mapping of linear B-cell epitopes in WNV NS1. We screened eight NS1-specific mAbs and antisera (polyclonal antibodies; pAbs) from mice immunized with recombinant NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. The screen using mAbs identified four WNV-specific (including Kunjin virus) epitopes, located at aa 21–36, 101–116, 191–206 and 261–276 in WNV NS1. However, using pAbs, only three WNV-specific epitopes were identified, located at positions 101–116, 191–206 and 231–246. Two of these epitopes (aa 21–36 and 261–276) had different reactivity with mAbs and pAbs. The knowledge and reagents generated in this study have potential applications in differential diagnostics and epitope-based marker vaccine development for WNV and viruses of the JEV serocomplex.


2021 ◽  
Author(s):  
Kaveri Krishnasamy ◽  
Gracy Fathima Selvaraj ◽  
Kiruba Ramesh ◽  
Padmaoriya Padmanabhan ◽  
Vidya Gopalan ◽  
...  

The emergence of a novel coronavirus in China in late 2019 has turned into a SARS-CoV-2 pandemic affecting several millions of people worldwide in a short span of time with high fatality. The crisis is further aggravated by the emergence and evolution of new variant SARS-CoV-2 strains in UK during December, 2020 followed by their transmission to other countries. A major concern is that prophylaxis and therapeutics are not available yet to control and prevent the virus which is spreading at an alarming rate, though several vaccine trials are in the final stage. As vaccines are developed through various strategies, their immunogenic potential may drastically vary and thus pose several challenges in offering both arms of immunity such as humoral and cell-mediated immune responses against the virus. In this study, we adopted an immunoinformatics-aided identification of B cell and T cell epitopes in the Spike protein, which is a surface glycoprotein of SARS-CoV-2, for developing a new Multiepitope vaccine construct (MEVC). MEVC has 575 amino acids and comprises adjuvants and various cytotoxic T-lymphocyte (CTL), helper T-lymphocyte (HTL), and B-cell epitopes that possess the highest affinity for the respective HLA alleles, assembled and joined by linkers. The computational data suggest that the MEVC is non-toxic, non-allergenic and thermostable with the capability to elicit both humoral and cell-mediated immune responses. The population coverage of various countries affected by COVID-19 with respect to the selected B and T cell epitopes in MEVC was also investigated. Subsequently, the biological activity of MEVC was assessed by bioinformatic tools using the interaction between the vaccine candidate and the innate immune system receptors TLR3 and TLR4. The epitopes of the construct were analyzed with that of the strains belonging to various clades including the new variant UK strain having multiple unique mutations in S protein. Due to the advantageous features, the MEVC can be tested in vitro for more practical validation and the study offers immense scope for developing a potential vaccine candidate against SARS-CoV-2 in view of the public health emergency associated with COVID-19 disease caused by SARS-CoV-2.


2014 ◽  
Vol 11 (1) ◽  
Author(s):  
Suvi Kuivanen ◽  
Jussi Hepojoki ◽  
Sirkka Vene ◽  
Antti Vaheri ◽  
Olli Vapalahti

2021 ◽  
Vol 12 ◽  
Author(s):  
Patrik D’haeseleer ◽  
Nicole M. Collette ◽  
Victoria Lao ◽  
Brent W. Segelke ◽  
Steven S. Branda ◽  
...  

Peptide-based subunit vaccines are coming to the forefront of current vaccine approaches, with safety and cost-effective production among their top advantages. Peptide vaccine formulations consist of multiple synthetic linear epitopes that together trigger desired immune responses that can result in robust immune memory. The advantages of linear compared to conformational epitopes are their simple structure, ease of synthesis, and ability to stimulate immune responses by means that do not require complex 3D conformation. Prediction of linear epitopes through use of computational tools is fast and cost-effective, but typically of low accuracy, necessitating extensive experimentation to verify results. On the other hand, identification of linear epitopes through experimental screening has been an inefficient process that requires thorough characterization of previously identified full-length protein antigens, or laborious techniques involving genetic manipulation of organisms. In this study, we apply a newly developed generalizable screening method that enables efficient identification of B-cell epitopes in the proteomes of pathogenic bacteria. As a test case, we used this method to identify epitopes in the proteome of Francisella tularensis (Ft), a Select Agent with a well-characterized immunoproteome. Our screen identified many peptides that map to known antigens, including verified and predicted outer membrane proteins and extracellular proteins, validating the utility of this approach. We then used the method to identify seroreactive peptides in the less characterized immunoproteome of Select Agent Burkholderia pseudomallei (Bp). This screen revealed known Bp antigens as well as proteins that have not been previously identified as antigens. Although B-cell epitope prediction tools Bepipred 2.0 and iBCE-EL classified many of our seroreactive peptides as epitopes, they did not score them significantly higher than the non-reactive tryptic peptides in our study, nor did they assign higher scores to seroreactive peptides from known Ft or Bp antigens, highlighting the need for experimental data instead of relying on computational epitope predictions alone. The present workflow is easily adaptable to detecting peptide targets relevant to the immune systems of other mammalian species, including humans (depending upon the availability of convalescent sera from patients), and could aid in accelerating the discovery of B-cell epitopes and development of vaccines to counter emerging biological threats.


2020 ◽  
Author(s):  
Sandeep Kumar Kushwaha ◽  
Veerbhan Kesarwani ◽  
Samraggi Choudhury ◽  
Sonu Gandhi ◽  
Shailesh Sharma

AbstractSARS-CoV-2 is a single-stranded RNA virus that has caused more than 0.29 million deaths worldwide as of May 2020, and influence of COVID-19 pandemic is increasing continuously in the absence of approved vaccine and drug. Moreover, very limited information is available about SARS-CoV-2 expressed regions and immune responses. In this paper an effort has been made, to facilitate vaccine development by proposing multiple epitopes as potential vaccine candidates by utilising SARS-CoV-2 transcriptome data. Here, publicly available RNA-seq data of SARS-CoV-2 infection in NHBE and A549 human cell lines were used to construct SARS-CoV-2 transcriptome to understand disease pathogenesis and immune responses. In the first step, epitope prediction, MHC class I and II gene identification for epitopes, population coverage, antigenicity, immunogenicity, conservation and crossreactivity analysis with host antigens were performed by using SARS-CoV-2 transcriptome, and in the second step, structural compatibility of identified T-and B-cell epitopes were evaluated with MHC molecules and B-cell receptors through molecular docking studies. Quantification of MHC gene expression was also performed that indicated high variation in allele types and expression level of MHC genes with respect to cell lines. In A549 cell line, HLA-A*30:01:01:01 and HLA-B*44:03:01:01 were highly expressed, whereas 92 variants of HLA-A*24 genes such as HLA-A*24:02:01:01, HLA-A*24:286, HLA-A*24:479Q, HLA-A*24:02:134 and HLA-A*24:02:116 were highly expressed in NHBE cell lines. Prevalence of HLA-A*24 alleles was suggested as risk factors for H1N1 infection, and associated with type-1 diabetes. HLA-C*03:03, linked with male infertility factors was also highly expressed in SARS-CoV-2 infected NHBE cell lines. Finally, three potential T-cell and five B-cell epitopes were selected for molecular docking studies with twenty-two MHC molecules and two B-cell receptors respectively. The results of in silico analysis indicated that proposed epitopes have high potential to recognize immune response of SARS-CoV-2 infection. This study will facilitate in vitro and in vivo vaccine related research studies.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 698
Author(s):  
Valentina A. Feodorova ◽  
Anna M. Lyapina ◽  
Maria A. Khizhnyakova ◽  
Sergey S. Zaitsev ◽  
Yury V. Saltykov ◽  
...  

The recent progress in immunoinformatics provided the basis for an accelerated development of target-specific peptide vaccines as an alternative to the traditional vaccine concept. However, there is still limited information on whether the in silico predicted immunoreactive epitopes correspond to those obtained from the actual experiments. Here, humoral and cellular immune responses to two major Yersinia pestis protective antigens, F1 and LcrV, were studied in human donors immunized with the live plague vaccine (LPV) based on the attenuated Y. pestis strain EV line NIIEG. The F1 antigen provided modest specific cellular (mixed T helper 1 (Th1)/Th2 type) and humoral immune responses in vaccinees irrespective of the amount of annual vaccinations and duration of the post-vaccination period. The probing of the F1 overlapping peptide library with the F1-positive sera revealed the presence of seven linear B cell epitopes, which were all also predicted by in silico assay. The immunoinformatics study evaluated their antigenicity, toxicity, and allergenic properties. The epitope TSQDGNNH was mostly recognized by the sera from recently vaccinated donors rather than antibodies from those immunized decades ago, suggesting the usefulness of this peptide for differentiation between recent and long-term vaccinations. The in silico analysis predicted nine linear LcrV-specific B-cell epitopes; however, weak antibody and cellular immune responses prevented their experimental evaluation, indicating that LcrV is a poor marker of successful vaccination. No specific Th17 immune response to either F1 or LcrV was detected, and there were no detectable serum levels of F1-specific immunoglobulin A (IgA) in vaccinees. Overall, the general approach validated in the LPV model could be valuable for the rational design of vaccines against other neglected and novel emerging infections with high pandemic potency.


2005 ◽  
Vol 117 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Danila Valmori ◽  
Naira E. Souleimanian ◽  
Charles S. Hesdorffer ◽  
Gerd Ritter ◽  
Lloyd J. Old ◽  
...  

2021 ◽  
Author(s):  
Patrik D'haeseleer ◽  
Nicole M Collette ◽  
Victoria Lao ◽  
Brent W Segelke ◽  
Steven S Branda ◽  
...  

Peptide-based subunit vaccines are coming to the forefront of current vaccine approaches, with safety and cost-effective production among their top advantages. Peptide vaccine formulations consist of multiple synthetic linear epitopes that together trigger desired immune responses that can result in robust immune memory. The advantages of peptide epitopes are their simple structure, ease of synthesis, and ability to stimulate immune responses by means that do not require complex 3D conformation. Identification of linear epitopes is currently an inefficient process that requires thorough characterization of previously identified full-length protein antigens, or laborious techniques involving genetic manipulation of organisms. In this study, we apply a newly developed generalizable screening method that enables efficient identification of B cell epitopes in the proteomes of pathogenic bacteria. As a test case, we used this method to identify epitopes in the proteome of Francisella tularensis (Ft), a Select Agent with a well-characterized immunoproteome. Our screen identified many peptides that map to known antigens, including verified and predicted outer membrane proteins and extracellular proteins, validating the utility of this approach. We then used the method to identify seroreactive peptides in the less characterized immunoproteome of Select Agent Burkholderia pseudomallei (Bp). This screen revealed known Bp antigens as well as proteins that have not been previously identified as antigens. The present workflow is easily adaptable to detecting peptide targets relevant to the immune systems of other mammalian species, including humans (depending upon the availability of convalescent sera from patients), and could aid in accelerating the discovery of B cell epitopes and development of vaccines to counter emerging biological threats.


2021 ◽  
Author(s):  
Dhrubajyoti Mahata ◽  
Debangshu Mukherjee ◽  
Vanshika Malviya ◽  
Gayatri Mukherjee

Diseases caused by Dengue (DENV) and Zika (ZIKV) viruses cause significant mortality and illness globally. Due to the high sequence similarity of the viral proteins and the purported cross-reactive immune responses against the viruses, we envisioned a common multi-epitope vaccine (MEV) against both viruses by adopting a novel approach of identifying “immunogenic hotspots”. These stretches of the structural and non-structural proteins are enriched with MHC class I and class II supertype-restricted T cell epitopes, and B cell epitopes, in addition to being highly conserved between different DENV serotypes and ZIKV. Such an approach ensures inclusion of multiple overlapping T and B cell epitopes common to both viruses, and also warrants high population coverage. Importantly, epitopes known to cause antibody-dependent-enhancement of infection have been excluded. These immunogenic hotspots have then been stitched together with linkers in-silico along with an adjuvant, CTxB to develop the MEV candidate. Four structural models of the MEV were selected on the basis of conformational preservation of CTxB, and their biophysical parameters, which also conserved the immunogenicity of the multiple epitopes. Importantly, each of the MEV candidates were found to interact with TLR4-MD2 complex by molecular docking studies, indicative of their ability to induce TLR-mediated immune responses.


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